Steady rest and indicator gauge assembly for shaft grinder



Jun 19. 9 R. A. FARNAM STEADY REST AND INDICATOR GAUGE ASSEMBLY FORSHAFT GRINDER 3 Sheets-Sheet 1 Filed April 21, 1955 IHWHI lgl lull! 42 W.INVENTOR;

ROY A. FARNAM BY V ' ATTORNEY A. FARNAM 2,750,715

June 19, 1956 STEADY REST AND INDICATOR GAUGE ASSEMBLY FOR SHAFT GRINDER3 Sheets-Sheet 2 Filed April 21, 1953 v INVENTOR. ROY A. FA'RNAMATTORNEY R. A. FARNAM STEADY REST AND INDICAT June 19, 1956 OR GAUGEASSEMBLY FOR SHAFT GRINDER 3 Sheets-Sheet 3 Filed April 2. 1953 mm mm IINVENTOR. ROY A. FARNAM ATTORNEY United States Patent STEADY REST ANDKNDICATOR GAUGE ASEEEMBLY FOR SHAFT GRINDER Roy A. Farnam, La Grande,Oreg. Application April 21, 1953, Serial No. 350,040 6 Claims. (Cl.51-405) This invention relates in general to the grinding of shafts and,in particular, to the grinding of the journal portions of a crank shaftof the type used in automotive vehicles and the like.

In such grinding, as is well known, the shaft is mounted at each end forrotation on the axis of the portion which is being ground and the shaftis then rotated while the rotating grinding wheel is maintained incontact with such shaft portion during the grinding operation. Since thegrinding wheel bears against that portion of the shaft which is beingground, it is desirable to provide some additional support or steadyrest for the shaft at this location to counteract any tendency for theshaft to be slightly bowed under pressure from the grinding wheel, alsoto eliminate any whipping or vibrating of the shaft during the grinding.

An object of the present invention is to provide an improved adjustablesteady rest assembly for a shaft, particularly a vehicle crank shaft,during the grinding.

A further object of the invention is to provide improved spring-loadedmeans which will engage the portion of the shaft being ground and opposethe pressure exerted on such portion by the grinding wheel and whichwill remain in constant contact with the shaft regardess of anyirregularities in the contacted shaft surface.

Another object of the invention is to provide a suitable gaugeattachment in the steady rest assembly which can be adjustably set forcooperation with the shaft-contacting, spring-loaded means and whichwill constantly gauge the grinding effected by the grinding wheel.

These objects and other incidental advantages I attain through thecombination and cooperation of the members of my steady rest assembly ashereinafter briefly described with reference to the accompanyingdrawings, in which:

Fig. l is a top plan view of a more or less standard type of crank shaftgrinding machine illustrating my steady rest assembly mounted on thesame;

Fig. 2 is a fragmentary section on line 22 of Fig. l but drawn to anenlarged scale and showing a side elevation of the entire steady restassembly;

Fig. 3 is a fragmentary sectional elevation of the upper portion of thesteady rest assembly of Fig. 2, drawn to a still larger scale;

Fig. 4 is a top plan view of the shaft-engaging bar of Fig. 3 and itspositioning screw, showing the same by themselves and entirely removedfrom the housing;

Fig. 5 is a top plan view of the gauge of the assembly and its extensionelement, the latter being shown in section;

Fig. 6 is a fragmentary sectional elevation similar to Fig. 3 butillustrating an optional modified form in which the shaft-engaging barand its positioning screw may be made; and

Fig. 7 is a top plan view of the shaft-engaging bar and the positioningscrew of Fig. 6 showing the same by themselves.

Referring first to Fig. 1, an automobile crank shaft 10 "ice is shownsupported between the head stock and tail stock of the grinding machine11. A central journal portion of this crank shaft 10 is shown inposition for grinding by the grinding wheel 12. The grinding wheel 12 ofthe grinding machine is mounted below the shield 13, the grinding wheelbeing axially adjustable in position, and the grinding wheel so arrangedas to be rotated rapidly by suitable means (not shown) as is customaryin grinding machines. My steady rest assembly, indicated in general bythe reference character 14, is laterally slidable on the machine 11 andis shown in the proper position opposite the grinding wheel 12.

Referring now to Fig. 2, the steady rest assembly includes a housing 15having a base portion which is slidably supported on a shoulder 16extending longitudinally on the grinding machine 11 and is clamped inany desired location by simple clamping means. A hinged arm support 17for the shaft 10 is pivotally mounted on a pin 18 and is raised intocontact with the under side of the shaft 10 by adjustment of a screw 19,the inner end of which screw bears against the inner end of the arm 17below the pin 18, as shown by the broken lines in Fig. 2. The arm 17 istipped with Babbitt metal or with other relatively soft metal on the tip17 so that the surface of the shaft 10 which is being ground will not beinjured by its engagement with the bottom arm 17. This type ofsupporting arm is well known and is in general use.

A shaft-engaging bar 20 is slidably mounted on the upper portion of thehousing 15 in such position as to enable the tip 20' of the bar toengage the shaft 10 on the opposite side from the grinding wheel 12.Consequently any pressure exerted by the bar 20 against the shaft 10during the grinding operation will be in opposition to the pressureexerted by the grinding wheel 12 against the shaft 10.

The inner end of the bar 20 (Fig. 3) has a central channel 21 leading infrom a larger end channel 22. A spring-loaded thrust element 23 has astem 24 with an enlarged outer portion 25, the diameters of the stem 24and enlarged portion 25 corresponding approximately to the diameters ofthe channels 21 and 22 respectively. A coil spring 26 extends around thestem 24 within the channel 22 with one end engaging the shoulder at theinner end of the channel 22 and the other end engaging the shoulder onthe stem formed by the enlarged portion 25. An aperture 27 extendstransversely through the bar 20 and a pin 28, carried on the stem 24,limits the travel of the stem 24, and thus the movement of the thrustelement 23 with respect to the bar 20, by engagement with the wall ofthe aperture 27.

An adjusting screw 29, having threaded engagement with a bushing in thehousing 15, and axially aligned with the stem 24 of the thrust element23, and having an external finger knob 30 for convenience in adjustment,bears against the thrust element 23 as shown in Fig. 3, for the purposeof urging the bar 20 against the shaft 10 with desired resilientpressure. At the start of the grinding operation, with the housing ofthe steady rest assembly in position opposite the grinding wheel, thebar 20 is first moved towards the shaft by adjusting the screw 29 untilthe tip 20' of the bar contacts the shaft 10. Then the screw 29 is givenslight additional rotation sufficient to bring the restraining pin 28approximately to the center of the aperture 27. This causes the tip 20'of the bar 20 to press against the shaft 10 constantly during therotation of the shaft 10 in the grinding operation, and enables thespring 26 to cushion and absorb the slight longitudinal vibrations ofthe bar 20 which would result from possible slight irregularities on theshaft surface. The spring 26 also enables the bar 20 to follow any'irregularities in the shaft surface and to continue to press against theshaft 10 in spite of the grinding of the shaft surface.

Calibrations (not shown) on the screw 29 and outside face of thethreaded bearing for the screw enable the position of the pin 28 in theaperture 27 to be gauged when the bar 29 is adjusted inasmuch as thepredetermined additional partial rotation of the screw 29, after the tip20 of the bar 29 is first brought into contact with the shaft 10, willcause the pin 28 to move from right to left in the aperture 27 (asviewed in Fig. 3) until the pin 28 reaches the approximate center of theaperture. The tip 20 of the bar 20 is preferably formed with Babbittmetal or other relatively soft metal to prevent any possible marring ofthe surface of the shaft 10.

A post 31 (see Figs. 2 and 3) is slidably mounted on the forward end ofthe bar 20 and is secured in desired set position by the screw 32. Agauge, indicated in general by the reference character 33, is secured onthe top of the housing 15' in the position shown in Figs. 2 and 3. Thisgauge 33 is of standard mechanical construction and the gauge housinghas an extension 34 which contains a spring-loaded plunger 41 (Fig.which actuates the mechanism rotating the indicating finger or pointeron the gauge. A spring-biased thrust rod 35 extends through acylindrical housing 36 which in turn is secured on the top of thehousing by the brackets 37, 37. A spring 38, extending around the rod35, in the cylindrical housing 36, has one end in engagement With thebushing 39 in the end of the housing nearest the gauge 33 and the otherend in engagement with a collar 40 secured on the thrust rod 35. Thus,as apparent from Fig. 5, the spring 38 tends to keep the thrust rod 35moved to the left (as viewed in Fig. 5) to the extent permitted by theengagement of the fixed collar 40 with the adjacent end bushing. Thecylindrical housing 36 is so positioned with respect to the gauge 33that the thrust rod 35 and the plunger 41 of the gauge 33 will be incontact with each other at all times and thus will be in contact whenthe gauge reading is zero.

When the shaft-engaging bar is set so as to contact the shaft 10 and theadjusting screw 29 is manipulated, as previously explained, to causespring pressure to be exerted on the shaft 20, the screw 32 is loosenedand the post 31 is manually adjusted so as to move the thrust rod 35,and therewith the gauge plunger 41, sumciently to cause a predeterminedreading to show on the gauge 33. Then the post 31 is clamped in thisposition by the set screw 32 and the entire assembly is ready for thegrinding operation.

As the shaft 19 rotates, any irregularities on the shaft surface willproduce slight endwise movements not only of the bar 20 but also of thethrust rod 35 and the gauge plunger 41, and these will be evidenced bymovement of the pointer or indicating finger on the gauge. Thus theoperator, by watching the gauge during the grinding, is constantlyinformed regarding the condition of the shaft surface which is beingground. Since the grinding wears away some of the shaft surface, thiscondition too will be properly indicated by the reduced reading on thegauge. In this way the operator can tell not only when surfaceirregularities on the shaft surface have been entirely removed but alsoexactly when the desired predetermined amount of the grinding of thesurface has been completed.

In .Figs. 6 and 7 I show a slightly modified shaft-engaging bar andadjusting screw, which may be substituted for the bar 20 and adjustingscrew 29 previously described. The modified bar 42 shown in thesefigures is solid throughout. The cooperating adjusting screw 43 on theother hand has a central channel 44 (Fig. 7) which extends inwardly froma larger end channel 4-5. A springloaded thrust element 46 has a stem47, slide-able in the channel 44, and a larger diameter collar 48,slidable in the end channel 45. A spring 49 has its ends in engagementwith the collar 48 and the shoulder at the inner termination of theenlarged channel 45 respectively. The stem 47 carries a pin 51 whichengages the wall of the aperture 50 to limit the movement of the thrustelement with respect to the screw 43. The tip 42' of this bar 42 isfinished in the same manner as the tip 20 of the bar 20, and a post 31is carried on the bar 42 in the same manner as the post 31 on the bar 20and is clamped in desired position by the screw clamp 32. Obviously theoperation is the same as with the bar 20 and its adjusting screw 29.

Minor modifications would be possible in my steady rest and indicatorgauge assembly without departing from the principle of the invention. Itis not my intention to confine my assembly to the exact details ofconstruction herein illustrated and described, but the particularconstruction which I have illustrated and shown I consider to be thepreferred manner of carrying out my invention. It is not my intention tolimit my invention otherwise than as set forth in the claims.

I claim:

1. In a shaft grinding device including means for mounting and rotatingthe shaft and a rotary grinding wheel adapted to bear against the shaftduring the grin ling operation, a steady rest housing, a shaft-en agingbar slidably supported in said housing and extending at right angles tothe axis of the grinding wheel and adapted to extend at right angles tothe shaft, located opposite the grinding wheel, said bar slidabletowards and away from the shaft, means for urging said bar against saidshaft, said means comprising a manually-operable positioning screw inaxial alignment with the longitudinal center line of said bar and aspring-loaded thrust element interposed between said positioning screwand the portion of said bar opposite from the shaft-engaging end of saidbar, a gauge, a post carried on said bar between the shaft-engaging endof said bar and said spring-loaded thrust element and adjustablethereon, and means con necting said post with said gauge, whereby whensaid bar is maintained in engagement with the shaft during the grindingall movement of said bar caused by said shaft will be indicated on saidgauge.

2. In a shaft grinding device including means for mounting and rotatingthe shaft and a rotary grinding wheel adapted to bear against the shaftduring the grinding operation, a steady rest housing mounted on saiddevice, a shaft-engaging bar supported in said housing and extending atright angles to the axis of the grinding wheel and located opposite thegrinding wheel, said bar slidable towards and away from the shaft, aspring-biased thrust element slidably mounted in the end of said baropposite from the shaft-engaging end of said bar, means limiting themovement of said thrust element with respect to said bar, amanually-operable positioning screw for said bar engaging said thrustelement, whereby said bar can be caused to press against the shaft withresilient predetermined pressure on the opposite side from the grindingwheel constantly during the grinding operation, a gauge mounted on saidhousing, a member carried on said bar and adjustable thereon, and meansconnecting said member with said gauge, whereby when said bar ismaintained in engagement with the shaft during the grinding all movementof said bar caused by said shaft will be indicated on said gauge.

3. In a shaft grinding device including means for mounting and rotatingthe shaft and a rotary grinding wheel adapted to bear against the shaftduring the grinding operation, a steady rest housing mounted on saiddevice, a shaft-engaging bar supported in said housing and extending atright angles to the axis of the grinding wheel and located Opposite thegrinding wheel, said bar slidable towards and away from the shaft, apositioning screw for said bar, a spring-loaded thrust element slidablymounted in the end of said positioning screw for engagement with theadjacent end of said bar, whereby said bar can be Caused to pressagainst the shaft with resilient predetermined pressure on the oppositeside from the grinding wheel constantly during the grinding operation, a

gauge mounted on said housing, a member carried on said bar between theshaft-engaging end of said bar and said spring-loaded thrust element andadjustable on said bar, and means connecting said member with saidgauge, whereby when said bar is maintained in engagement with the shaftduring the grinding all movement of said bar caused by said shaft willbe indicated on said gauge.

4. In a shaft grinding device including means for mounting and rotatingthe shaft and a rotary grinding wheel adapted to bear against the shaftduring the grinding operation, a steady rest housing mounted on saiddevice, a shaft-engaging bar slidably supported in said housing andextending at right angles to the axis of the grinding wheel and oppositethe grinding wheel, said bar slidable towards and away from the shaft, amanually-operable positioning screw for said bar, a spring-biased thrustelement slidably mounted in the end of said positioning screw forengagement with the adjacent end of said bar, means limiting themovement of said thrust element with respect to said positioning screw,whereby said bar can be caused to press against the shaft with resilientpredetermined pressure on the opposite side from the grinding wheelconstantly during the grinding operation, a gauge mounted on saidhousing, a member carried on said bar and adjustable thereon, and meansconnecting said member with said gauge, whereby when said bar ismaintained in engagement with the shaft during the grinding all movementof said bar caused by said shaft will be indicated on said gauge.

5. A shaft grinding device of the character described including meansfor mounting and rotating the shaft, a rotary grinding wheel adapted tobear against the shaft during the grinding operation, a steady resthousing mounted on said device and movable in parallelism with the axisof the grinding wheel, a shaft-engaging bar slidably supported in saidhousing and extending at right angles to the axis of the grinding wheeland positioned opposite the grinding wheel, said bar slidable towardsand away from the shaft, a spring-biased thrust element slidably mountedin the end of said bar opposite from the shaftengaging end of said bar,means limiting the movement of said thrust element with respect to saidbar, a manuallyoperable positioning screw for said bar engaging saidthrust element, whereby said bar can be caused to press against theshaft with resilient predetermined pressure on the opposite side fromthe grinding wheel constantly during the grinding operation, a gaugemounted on said housing, an actuating element in said gauge, a membercarried on said bar and adjustable thereon, and a spring- 6 loadedthrust rod connecting said member with said gauge actuating element,whereby when said bar is maintained in engagement with the shaft duringthe grinding all movement of said bar caused by said shaft will beindicated on said gauge.

6. A shaft grinding device of the character described including meansfor mounting and rotating the shaft, a rotary grinding wheel adapted tobear against the shaft during the grinding operation, a steady resthousing mounted on said device and movable in parallelism with the axisof the grinding wheel, a shaft-engaging bar slidably supported in saidhousing extending at right angles to the axis of the grinding wheel andpositioned opposite the grinding wheel, said bar slidable towards andaway from the shaft, a manually-operable positioning screw for said bar,a spring-biased thrust element slidably mounted in the end of saidpositioning screw for engagement with the adjacent end of said bar,means limiting the movement of said thrust element with respect to saidpositioning screw, whereby said bar can be caused to press against theshaft with resilient predetermined pressure on the opposite side fromthe grinding wheel constantly during the grinding operation, a gaugemounted on said housing, a plunger in said gauge, a post carried on saidbar and adjustable thereon, and a spring-loaded thrust rod connectingsaid post with said gauge plunger, whereby when said bar is maintainedin engagement with the shaft during the grinding all movement of saidbar caused by said shaft will be indicated on said gauge.

References Cited in the file of this patent UNITED STATES PATENTS732,314 Norton June 30, 1903 1,078,561 Shearer Nov. 11, 1913 1,299,838Keller Apr. 8, 1919 1,317,227 Scusa Sept. 30, 1919 1,394,324 MatthewsOct. 18, 1921 1,615,060 Arnold Jan. 18, 1927 2,099,161 De Leeuw Nov. 16,1937 2,160,378 Balsiger May 30, 1939 2,419,406 Koebbe Apr. 22, 19472,525,364 Mennesson Oct. 10, 1950 FOREIGN PATENTS 121,859 Sweden Sept.5, 1946 OTHER REFERENCES Publication: American Machinist, March 11,1948, page 187.

